Thráin II
Thorin II	Frerin	Dís
	Fíli		Kíli

The third child of Thráin II of Durin's Folk, and thus a direct descendant of the royal line of the House of Durin. Dís was born in the last days of the Kingdom under the Mountain, and had two elder brothers, Thorin (later famed as Thorin Oakenshield) and Frerin. She was just ten years old when the Dragon Smaug appeared out of the North to sack the Lonely Mountain, but she was able to escape with her family into the wilds of Middle-earth.³

The exiles of Durin's Folk wandered southwards from Erebor, settling for a time with their few followers in Dunland, under the western feet of the Misty Mountains near their southern end. It was during this time that the great War of the Dwarves and the Orcs was fought, and in its climactic Battle of Azanulbizar Dís lost her brother Frerin. After the War, Dís' father Thráin abandoned Dunland and led his family northward again, eventually settling in the Blue Mountains on the western edge of Eriador.

Thráin and his people settled in the Blue Mountains in III 2802, but we know little of Dís' history after this date. She was said to have been one of very few female Dwarves among this people, and it is clear that at some point in the following decades she chose a husband. Nearly sixty years after her arrival in the Mountains, Dís had a son, Fíli, and five years later another, named Kíli. With her elder brother Thorin being childless, and Frerin having been slain in battle, Dís' sons were therefore the heirs of the royal line of Durin's Folk.⁴

Of Dís' later life we know almost nothing. She was likely still alive in III 2941 (when she would have been 181 years old - not extraordinarily old for a Dwarf), when she would have seen her brother Thorin set out on the Quest of Erebor, taking her sons Fíli and Kíli among his party. Thorin's company succeeded in reclaiming Erebor, but Thorin himself, and both of Dís' sons, were slain in the attempt. After this, many Dwarves gathered at the newly-refounded Kingdom under the Mountain, but we have no way to know whether Dís herself made the journey back to her childhood home. If she lived a typical Dwarf lifespan, Dís would have lived until about the year III 3010, thus not surviving to see the War of the Ring and the end of the Third Age.

Dís is notable as being the only Dwarf-woman recorded in the histories of Middle-earth. The Dwarves were in general highly secretive about their womenfolk, and very little is known about their place in Dwarf society. They were said to make up only about a third of the population, and be physically almost indistinguishable from male Dwarves (at least to the eyes of a non-Dwarf). Among the Longbeards, and perhaps therefore among all Dwarves, women do not appear to have been able to inherit titles, but they seem to otherwise played a relatively independent role in Dwarf society. We're told, for example, that many chose not to take husbands (a fact that accounts for the generally low rate of increase in Dwarf populations).